Scaling a rocky wall, 5 or 500 meters tall, with a slight slope or a sheer vertical drop; harnessed to ropes or completely free; wearing ballet slippers, bare feet or hiking boots: whatever your technique, this is free climbing (free from artificial anchors, not ropes!), also known as sports climbing (there are even competitions).
It is not a difficult sport, nor is it intrinsically dangerous as long as it is done with the right training and following certain safety rules. The first level (I) is like climbing a ladder.
The second and third levels (II and III) can be done the first time by 90% of the people.
The fourth level (IV) starts to get interesting…
The 9a (XII) level is the most difficult climb today.